The long-term objective of this proposal is to resolve one of the most controversial and perplexing problems in lung research today, i.e., the role of vitamin E in the response of lung tissue to oxidant gas (NO2 or O3) exposure. During the past year, we have developed a new procedure for vitamin E analysis in the lung that requires only 30 Mug of tissue (dry weight) or less and that permits an exciting new approach to the problem. Microdissections or cryostat sections of specific anatomic structures or areas are used as source material for analysis by gas chromatography-mass spectrometry. When combined with structure analysis by light and electron microscopy, cytodynamic analysis using DNA extraction and scintillation counting and/or autoradiography after 3H-thymidine incorporation, performed on tissue from the same animal, they become reliable tools to determine the role of vitamin E in the cellular response of lung tissue to oxidant gases. The specific aims are to (l) determine the dynamics of vitamin E within designated structures of the lung (i.e., focal area of response--terminal bronchiole and proximal alveolar duct; peripheral parenchyma; airway epithelium; and blood vessels) during injury and repair and after long-term exposures; (2) determine to what extent supplemented or depleted diets alter the level of vitamin E in the general tissue and in the specific anatomic sites and relate these data to the structural and cytodynamic response; (3) determine how vitamin E levels relate to four increasingly sensitive rat models (inherently resistant nursing pups; the transitional postweaning animal; the "standard: sensitive young-adult animal; and the hypersensitive nursing maternal animal); and (4) prepare subcellular fractions of tissue and lavages and analyze them for their vitamin E content to determine whether the levels in specific fractions are preferentially changed by oxidant gas exposure. Data compiled on an individual-animal basis will be used for comparison between animals in the same group, and averaged data for each model will be used to compare models. We feel confident that a careful assessment of the data will permit us to clearly determine whether vitamin E plays a significant role in the response of lung tissue to oxidant gases and to make it possible to adequately advise the public.